GPT-5.1 vs o3 Pro
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5.1 and o3 Pro.
GPT-5.1
GPT-5.1 is the latest frontier-grade model in the GPT-5 series, offering stronger general-purpose reasoning, improved instruction adherence, and a more natural conversational style compared to GPT-5. It uses adaptive reasoning...
o3 Pro
The o-series of models are trained with reinforcement learning to think before they answer and perform complex reasoning. The o3-pro model uses more compute to think harder and provide consistently...
Technical Specifications
| Specification | GPT-5.1 | o3 Pro |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 400,000 tokens | 200,000 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-11-13 | 2025-06-10 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.1
$1.25
o3 Pro
$20.00
Output Price per Million Tokens
GPT-5.1
$10.00
o3 Pro
$80.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5.1 Quirks & Gotchas
No developer gotchas reported.
o3 Pro Quirks & Gotchas
No developer gotchas reported.